A 15-year-old Bronx teenager was stabbed to death during a fight in which bullying was the suspected root of the clash.

In addition to the 15-year-old Matthew McRee, a 16-year-old, Ariane Laboy, was also stabbed during the confrontation at the Urban Assembly School for Wildlife Management. He was critically wounded, with stab wounds on his chest, arm, and side.

Police said that the attacker was 18-year-old Abel Cedeno, who was in the literature class with the two other teens as well as 20 other students. Sources claimed that Cedeno was being bullied at school.

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“We believe this argument has been going on for about two weeks into the school year,” NYPD Chief of Detectives Robert Boyce said. “A fight erupted today after some back and fourth about a half-hour into the class.”

After the stabbing, Cedeno freely gave his 3-inch blade to a school official and then sat in the assistant principal’s office until police were called. As of Wednesday, he was being interviewed by police, and no charges have yet been filed.

“This is a painful, painful tragedy for the families involved,” Mayor de Blasio said. “We will do all we can to support them and the community, which is reeling right now from this incident.”